If you blew out all the hard lines with compressed air, you must have done that from the end where the soft line attaches, otherwise you would have to remove the hardlines from the master cylinder and cleared them out from there. with nothing to support this theory, It is possible by blowing back through the system you forced all the fluid from the master cylinder back into the resevoir. if that is so, you would need to "bench bleed" the master cylinder to force all the air out with brake fluid, otherwise you'll always be introducing air into the system as you try to bleed. Several discussions on bench bleeding on the web.
btw, normal procedure for standard brake bleeding is to go to wheel cylinder most distant from the resevoir and bleed, proceeding to that fashion until you reach the front caliper nearest the resevoir.